linux使用shared_ptr出现错误

    我在不同的系统下采用下面的方式使用shared_ptr以及vector:

std::vector<const std::shared_ptr<Object> > pointer_arrays;std::vector<const std::shared_ptr<Object > >::const_iterator pointer_Iter;

并采用如下初始化：

const std::shared_ptr<WordData> object(new Object);wordDataTab.push_back(object);

这样在mac os下面编译，通过并且获得正确的结果。但是我在centos 下的使用gcc编译这段代码时出现如下的编译错误：

./test.cpp:19:   instantiated from here/usr/lib/gcc/x86_64-redhat-linux6E/4.4.7/../../../../include/c++/4.4.7/ext/new_allocator.h:95: error: invalid conversion from ‘const void*’ to ‘void*’/usr/lib/gcc/x86_64-redhat-linux6E/4.4.7/../../../../include/c++/4.4.7/ext/new_allocator.h:95: error:   initializing argument 1 of ‘void operator delete(void*)’In file included from /usr/lib/gcc/x86_64-redhat-linux6E/4.4.7/../../../../include/c++/4.4.7/bits/char_traits.h:41,                 from /usr/lib/gcc/x86_64-redhat-linux6E/4.4.7/../../../../include/c++/4.4.7/ios:41,                 from /usr/lib/gcc/x86_64-redhat-linux6E/4.4.7/../../../../include/c++/4.4.7/ostream:40,                 from /usr/lib/gcc/x86_64-redhat-linux6E/4.4.7/../../../../include/c++/4.4.7/iostream:40,                 from ./test.h:12,                 from ./test.cpp:9:/usr/lib/gcc/x86_64-redhat-linux6E/4.4.7/../../../../include/c++/4.4.7/bits/stl_algobase.h: In static member function ‘static _BI2 std::__copy_move_backward<true, false, std::random_access_iterator_tag>::__copy_move_b(_BI1, _BI1, _BI2) [with _BI1 = const std::shared_ptr<Object>*, _BI2 = const std::shared_ptr<Object>*]’:/usr/lib/gcc/x86_64-redhat-linux6E/4.4.7/../../../../include/c++/4.4.7/bits/stl_algobase.h:595:   instantiated from ‘_BI2 std::__copy_move_backward_a(_BI1, _BI1, _BI2) [with bool _IsMove = true, _BI1 = const std::shared_ptr<Object>*, _BI2 = const std::shared_ptr<Object>*]’/usr/lib/gcc/x86_64-redhat-linux6E/4.4.7/../../../../include/c++/4.4.7/bits/stl_algobase.h:605:   instantiated from ‘_BI2 std::__copy_move_backward_a2(_BI1, _BI1, _BI2) [with bool _IsMove = true, _BI1 = const std::shared_ptr<Object>*, _BI2 = const std::shared_ptr<Object>*]’/usr/lib/gcc/x86_64-redhat-linux6E/4.4.7/../../../../include/c++/4.4.7/bits/stl_algobase.h:676:   instantiated from ‘_BI2 std::move_backward(_BI1, _BI1, _BI2) [with _BI1 = const std::shared_ptr<Object>*, _BI2 = const std::shared_ptr<Object>*]’/usr/lib/gcc/x86_64-redhat-linux6E/4.4.7/../../../../include/c++/4.4.7/bits/vector.tcc:308:   instantiated from ‘void std::vector<_Tp, _Alloc>::_M_insert_aux(__gnu_cxx::__normal_iterator<typename std::_Vector_base<_Tp, _Alloc>::_Tp_alloc_type::pointer, std::vector<_Tp, _Alloc> >, _Args&& ...) [with _Args = const std::shared_ptr<Object>&, _Tp = const std::shared_ptr<Object>, _Alloc = std::allocator<const std::shared_ptr<Object> >]’/usr/lib/gcc/x86_64-redhat-linux6E/4.4.7/../../../../include/c++/4.4.7/bits/stl_vector.h:741:   instantiated from ‘void std::vector<_Tp, _Alloc>::push_back(const _Tp&) [with _Tp = const std::shared_ptr<Object>, _Alloc = std::allocator<const std::shared_ptr<Object> >]’

可以看到原来是stl_vector与const std::shared_ptr<Object> 

结合使用出现问题，于是我这样定义：

std::vector<std::shared_ptr<Object> > pointer_arrays;std::vector<std::shared_ptr<Object > >::const_iterator pointer_Iter;

再次编译，通过了。

这是因为：

shared_ptr<const T> p; is similar to const T * p; (or, equivalently, T const * p;), that is, the pointed object is const whereas const shared_ptr<T> p; is similar to T* const p; which means that p is const. In summary:

shared_ptr<T> p;             ---> T * p;                                    : nothing is constconst shared_ptr<T> p;       ---> T * const p;                              : p is constshared_ptr<const T> p;       ---> const T * p;       <=> T const * p;       : *p is constconst shared_ptr<const T> p; ---> const T * const p; <=> T const * const p; : p and *p are const.

The same holds for weak_ptr and unique_ptr.

这里const shared_ptr<T> p;p是const的，所以指针是固定的，但指针指向的内容是可以变的。而在vector的allocator函数不能将const void指针变为void指针，所以出现了编译错误。